The law of optics applicable in this scenario is the Snell's Law which states that the ratio of the index of refraction of two media is equal to the ratio of the sine of the angle of reflection and sine of the angle of refraction. In equation form:
n₁ / n₂ = sin b / sin a
In this situation, 0.782 would be rounded to 0.8
how to round a decimal: take the underlined number and look to the number located to the RIGHT of the underlined number, if the number to the right of the underlined number is 4 or less you leave the underlined number as is - but if the number right to underlined number is 5 or greater you round the underlined number up by one
ex. 1.83 [round to the nearest tenth]
answer: 1.80
instead of keeping the 3 [hundredth] you turn it into a 0.
C = πd ( in terms of the diameter ), C = 2πr ( in terms of the radius )
